The use of wireless communication systems by which to communicate telephonically has achieved wide levels of usage in recent years. Advancements in communication technologies have permitted the development, and popular usage, of new types of communication devices, of improved performance capabilities, of increased portability, and of increased affordability.
In contrast to conventional, wire-line communication systems, a communication channel formed to extend between a sending station and a receiving station in a wireless communication system, is formed of one or more radio channels. A radio channel is defined upon a portion of the electromagnetic frequency spectrum. Information to be communicated by the sending station to the receiving station is converted into a form, typically by way of a modulation process, to permit its communication upon the radio channel. Because of the use of radio channels to effectuate communication between the sending and receiving stations, conventional wire-line connections are not required to be positioned to extend between such sending and receiving stations. The costs associated with the installation of a wireless communication system, as a result, are sometimes less than the costs required to install a wire-line system. Utilization of a wireless communication system is also advantageous in that communication therethrough can be effectuated from locations at which the installation of a wire-line connection would be impractical.
A cellular communication system is exemplary of a wireless, multi-user communication system which has achieved wide levels of usage in recent years. Telephonic communication, of both voice and data messages, is possible by way of a cellular communication system. A conventional cellular communication system includes a network infrastructure, including a plurality of fixed-site base stations installed throughout a geographical area. Telephone communications are effectuated by way of the fixed-site base stations with mobile stations positioned within the geographical area encompassed by the network infrastructure.
Various standards have been promulgated to define the operational requirements of various types of cellular communication systems. Cellular communication systems have been correspondingly constructed to comply with such standards. For instance, the TIA/EIA-95-B interim standard, promulgated by the EIA/TIA, is exemplary of a standard which sets forth operational requirements of a cellular communication system. The TIA/EIA95-B standard is a CDMA (code-division multiple-access) cellular communication system.
In a CDMA system, a plurality of concurrently generated communication signals, such as those generated during operation of a plurality of mobile stations, are transmitted upon a common portion of the electromagnetic spectrum. Each communication signal is uniquely encoded at a sending station, and a channel is defined by the unique code by which a communication signal is encoded. A receiving station uniquely decodes the uniquely encoded communication signal, thereby to recover the informational content thereof. In a multi-user cellular communication system, the concurrently-generated communication signals are generated by the transmitter portions of the radio base stations and mobile stations of the system. And, the receiver portions of such regular base stations and mobile stations are operable to receive, and thereafter decode, such communication signals.
Conventionally, when a message, a xe2x80x9ccallxe2x80x9d, is to be terminated at a mobile station, the network infrastructure broadcasts a paging message to alert the mobile station of the message. Responsive to the detection of the page, the mobile station is caused to perform various operations to receive the terminating message. Between calls, portions of the mobile station are usually powered-down to reduce power consumption at the mobile station. By reducing power consumption, the battery life of a battery power supply used to power the mobile station can be increased.
In the TIA/EIA-95-B standard, for instance, a paging channel slot defined upon a paging channel is assigned to a group of mobile stations. When a message is to be terminated at a mobile station, a page is broadcast to the mobile station during the paging channel slot assigned to the mobile station. The mobile xe2x80x9cwakes-upxe2x80x9d prior to its designed pager slot to receive the message during that slot. The paging channel slot is defined in a manner such that the paging channel slot assigned to a particular mobile station repeats at regular intervals, thereby defining a paging channel slot cycle.
The mobile station must be powered to an extent to permit its detection of a paging message broadcast during the paging channel slot, but, during other times, the mobile station is able to power-down and enter a standby mode, thereby to reduce power consumption of the mobile station. Additional details of the manner by which a mobile station is paged in a cellular communication system constructed pursuant to the TIA/EIA-95-B standard is described in the TIA/EIA-95-B specification, and the contents of which are incorporated herein in their entirety.
Proposals have been set forth for a new third-generation (3G), cellular communication system standard, referred to as the cdma2000 standard. The cdma2000 standard is sometimes also referred to as an IS-95C standard or IS-2000 standard. Proposals set forth in such standard provide for the communication of both voice and data messages. Various of such proposals set forth in the cdma2000 standard provide for the effectuation of communication in more efficient manners than permitted in existing systems.
For instance, the cdma2000 standard provides for a forward link quick-paging channel (F-QPCH) upon which indications, i.e., paging-bits are broadcast to a mobile station when a message is to be terminated at the mobile station. Transmission of the page indication bits permits a mobile station to determine quickly if a paging signal is to be transmitted to the mobile station to alert the mobile station of a terminating message to be terminated thereat. When a page is to be broadcast, a pair of page indication bits are first transmitted to the mobile station to indicate to the mobile station that a paging message is to be broadcast during a subsequent paging channel slot. Thereby, the mobile station is alerted to power-up to detect the subsequently-transmitted page.
In the absence of page indication bits, the mobile station is able to quickly determine that a page shall not be broadcast during a subsequent paging channel slot. The mobile station can power-down, thereby to conserve power. Thereby , power consumption of the mobile station is reduced in the event that no page indication bits are broadcast.
While such mechanism provides the possibility of improved power consumption characteristics of the mobile station, the existing manner by which the mobile station makes use of the page indication bits is strictly construed. Existing mobile station methodology as set forth in the TIA contributions for the cdma2000 standard utilizes a prescribed analysis of the page indication bits. Namely, if the first of a pair of indication bits is of a logical zero value the mobile station powers-down to a standby mode, thereby to ignore a second paging bit of the pair as well as to remain in the standby mode for a subsequent paging channel slot. Conversely, if the first paging bit is of a logical one value, the mobile station must receive the second paging bit prior to determining its subsequent operation. If the second paging bit is also of a logical one value, confirmation is made of the value of the first-detected paging bit. And, the mobile station is caused to power-up to detect and decode the page broadcast on a subsequent paging channel slot. If, conversely, the second paging bit of the pair of page indication bits is of a logical zero value, the mobile station thereafter powers-down to a standby mode and does not remain powered-up during a subsequent paging channel slot.
The existing methodology incorporates inflexible rules which are unpermitting of variation to take into account the varying environmental conditions and changes in system operation.
A manner to permit more flexible use of the page indication bits broadcast on a quick paging channel would facilitate improved operation of the mobile station.
It is in light of this background information related to paging of a radio receiving device that the significant improvements of the present invention have evolved.
The present invention, accordingly, advantageously provides apparatus, and an associated method, by which to selectively make use of page indication bits, such as the page indication bits defined in the cdma2000 specification, used to alert a mobile station of a page to be broadcast thereto.
Operation of an embodiment of the present invention provides a dynamic manner by which to selectively utilize page indication bits broadcast upon a quick paging channel (F-QPCH)defined in a cdma2000 cellular communication system. Determination is made of the likelihood that the values of the page indication bits are accurate. Responsive to such a determination, selection is made as to the manner, and if, the page indication bits are utilized at the mobile station to facilitate effectuation of paging operations at a mobile station. Operation of an embodiment of the present invention facilitates a reduction in power consumption requirements of a mobile station, as well as also providing for improved paging reliability at the mobile station.
In one implementation, when a determination is made that the operational conditions indicate that the values of the page indication bits, when received at the mobile station, are likely to be accurate, viz., are likely to correspond in value to the values of such page indication bits transmitted by the network infrastructure to the mobile station, only a single one of a pair of page indication bits is utilized by a mobile station to determine whether a page is to be broadcast to the mobile station. Reduced power consumption of the mobile station is thereby permitted as the value of only a single paging bit need be determined to select whether to power-down to a standby mode or to power-up during a subsequent paging channel slot to receive and decode a paging message broadcast thereon.
A determination is made, e.g., of signal quality measures including signal quality levels of the page indication bits responsive to the operating parameter, the power-up schedule of the mobile station due the other (non-page related) factors, the importance level associated with receiving a page, and any user choices relative to the priority of pages versus power conservation.
In another implementation, if a determination is made that communication conditions prevent assurances that a single paging bit is likely to be accurate, the mobile station is caused to be operated to determine values of both page indication bits of a pair of page indication bits and to select whether to maintain the mobile station in a powered-up mode during a subsequent paging channel slot responsive to determination of values of both of the page indication bits. Soft combining, for instance, of the two page indication bits can be performed to determine the values of the page indication bits.
In another implementation, if a determination is made that the values of the page indication bits are not likely to be valid or if the mobile station has other reasons to be powered up during the page slot, the mobile station is caused not to determine values of the page indication bits, and, instead, to tune to the paging channel during the paging channel slot assigned to the mobile station and to determine therefrom whether a paging message is broadcast thereto.
As the operational conditions in which the mobile station is operated is susceptible to change over time, operation of the mobile station is correspondingly caused to change with changing operational conditions. Thereby, a dynamic manner is provided by which to efficiently determine whether a paging message is broadcast to the mobile station, depending upon the operational conditions of the communication system.
In these and other respects, therefore, apparatus, and an associated method is provided by which to operate a radio device in a selected manner to receive paging messages. The radio device is operable in a radio communication system in which paging messages are selectively transmitted to the radio device upon a paging channel slot assigned to the radio device, the paging channel slot being defined upon a paging channel. Page indication bits are transmitted to the radio device at time intervals corresponding to the paging channel slot, and the page indication bits are of values representative of transmission of a paging message upon a paging channel slot. A determiner is coupled to receive indications of an operating parameter of signal conditions related to transmission of the page indication bits to the radio device. The determiner determines signal quality levels of the page indication bits responsive to the operating parameter. A selector is coupled to receive indications of determinations made by the determiner. The selector is operable responsive to the indications of the determinations by the determiner to select the selected manner by which to operate the radio device to receive the paging message.